public class Rectangle extends Shape {
    private double bian;

    public double getBian() {
        return bian;
    }

    public void setBian(double bian) {
        this.bian = bian;
    }

    @Override
    public void calculateArea() {
        double area = bian * bian;
        System.out.println("正方形的面积为："+area);
    }

    @Override
    public void calculatePerimeter() {
        double perimeter = bian * 4;
        System.out.println("正方形的周长为："+perimeter);
    }
}
